Abstract: A flexible printed circuit board includes a first flexible unit and a second flexible unit, where the first flexible unit includes a first connecting portion and a plurality of first wires, and each of the first wires includes a welding point located at the first connecting portion; each of the welding points is provided with a first connecting structure, and the welding point is electrically connected to the first connecting structure; the second flexible unit includes a first face and a second face, where the first face is located on a side of the second flexible unit facing away from the first flexible unit; the second flexible unit further includes a second connecting portion and a plurality of second wires; the second connecting portion is provided with a plurality of through holes, and the plurality of through holes are provided in one-to-one correspondence to the plurality of second wires.

Abstract: Embodiments include semiconductor packages. A semiconductor package includes a hybrid interposer with a first region and a second region. The first region is comprised of glass or low thermal conductive materials, and the second region is comprised of silicon or diamond materials. The semiconductor package includes a first die on the first region of the hybrid interposer, a second die on the second region of the hybrid interposer, and an integrated heat spreader over the first die, the second die, and the hybrid interposer. The hybrid interposer includes first and second interconnects, where the first interconnects vertically extend from a bottom surface of the first region to a top surface of the first region, and where the second interconnects vertically extend from a bottom surface of the second region to a top surface of the second region. The first interconnects are through-glass vias, and the second interconnects are through-silicon vias.

Abstract: Methods and systems for providing a cold plate assembly include providing a base and a cover. The cover can be fixedly coupled to the base. Each of the base and the cover can include spaced internal ribs, which can form flow paths when the base and cover are fixedly coupled together. The internal ribs of the base and the cover can have spaced tabs that can be fixedly coupled to the other of the base or the cover. The base and the cover may also include spaced external or outer sacrificial ribs.

Abstract: A flip-chip packaging substrate and a method for fabricating the same are disclosed. The method includes stacking a plurality of insulating layers having conductive posts in a manner that the conductive posts are stacked on and in contact with one another. The insulating layers and the conductive posts serve as a core layer structure of the flip-chip packaging substrate. As such, the conductive posts having small-sized end surfaces can be fabricated according to the practical need. Therefore, when the thickness of the core layer structure is increased, the present disclosure not only increases the rigidity of the flip-chip packaging substrate so as to avoid warping, but also ensures the design flexibility of the small-sized end surfaces of the conductive posts, allowing high-density electrical connection points and fine-pitch and high-density circuit layers to be fabricated on the core layer structure.

Abstract: A system for providing selective adhesion printed circuit board (PCB) production comprises a conveyor mechanism, a curing system, and a computer. The conveyor mechanism is configured to convey a series of selective adhesion blanks, wherein each selective adhesion blank is utilized to produce a PCB and includes a flexible film, a substrate, a conductive layer, and a curable adhesive. The conductive layer is formed from electrically conductive material and adhered to the substrate. The curable adhesive is positioned between the flexible film and the conductive layer and is configured to selectively bond with the conductive layer when the curable adhesive is cured. The curing system is configured to cure the curable adhesive. The computer includes a processing element configured or programmed to: receive a plurality of PCB designs, and direct the curing system to cure the curable adhesive of a plurality of selective adhesion blanks for each PCB design.

Abstract: Provided are a printed circuit board and a method for manufacturing the same, the printed circuit board including: an insulating member; a first pad disposed in the insulating member; a plurality of first vias respectively disposed on a lower side of the first pad in the insulating member and connected to the first pad; and a second via disposed on an upper side of the first pad in the insulating member and connected to the first pad.

Abstract: Provided is a technique that can achieve an insulating layer with small surface undulations and can suppress a haloing phenomenon in manufacturing a printed wiring board even when using a thin resin composition layer. Specifically, provided is a method for manufacturing a printed wiring board that includes the steps of: (A) preparing a resin sheet with an inorganic layer including (i) a support with an inorganic layer including an inorganic layer, a support in contact with the inorganic layer, and a release layer and (ii) a resin composition layer in contact with the release layer of the support with an inorganic layer; (B) laminating the resin sheet with an inorganic layer onto an internal layer substrate so that the resin composition layer of the resin sheet with an inorganic layer is in contact with the internal layer substrate; (C) curing the resin composition layer to form an insulating layer; and (D) perforating the insulating layer.

Abstract: A circuit board according to an embodiment includes: an insulating layer including a through hole and a via disposed in the through hole and wherein the via including a first metal layer on an upper surface of the insulating layer and an inner wall of the through hole; and a second metal layer disposed in the through hole, and the an upper surface of the second metal layer includes a protruding portion that does not overlap an upper surface of the insulating layer in a vertical direction and is located higher than the first metal layer.

Abstract: A polymer composition for use in an electric circuit protection device is provided. The polymer composition comprises a polymer matrix that includes a thermotropic liquid crystalline polymer. The polymer composition exhibits an in-plane thermal conductivity of about 3.5 W/m-K or more as determined in accordance with ASTM E1461-13 and a melt viscosity of from about 1 to about 100 Pa-s as determined in accordance with ISO Test No. 11443:2014 at a temperature 15° C. higher than the melting temperature.

Abstract: A panel type fan-out wafer level package with embedded film type capacitors and resistors is described. The package comprises a silicon die at a bottom of the package wherein a top side and lateral sides of the silicon die are encapsulated in a molding compound, at least one redistribution layer connected to the silicon die through copper posts contacting a top side of the silicon die, at least one embedded capacitor material (ECM) sheet laminated onto the package, and at least one embedded resistor-conductor material (RCM) sheet laminated onto the package wherein the at least one redistribution layer, capacitors in the at least one ECM, and resistors in the at least one RCM are electrically interconnected.

Abstract: An electronic package is provided and includes an electronic element, an intermediary structure disposed on the electronic element, and a heat dissipation element bonded to the electronic element through the intermediary structure. The intermediary structure has a flow guide portion and a permanent fluid combined with the flow guide portion so as to be in contact with the electronic element, thereby achieving a preferred heat dissipation effect and preventing excessive warping of the electronic element or the heat dissipation element due to stress concentration.

Abstract: A flexible circuit board according to an embodiment includes a first signal line extending on a first plane, a first dielectric extending in an extension direction of the first signal line while being in contact with the first signal line, a second signal line extending on a second plane parallel with the first plane, and a second dielectric extending in an extension direction of the second signal line while being in contact with the second signal line. The first signal line includes a first part overlapped with the second signal line and a second part not overlapped with the second signal line when viewed in a normal direction of the first plane, and the second signal line includes a first part overlapped with the first signal line and a second part not overlapped with the first signal line when viewed in the normal direction.

Abstract: A method for manufacturing a laminated structure, or a method for manufacturing a liquid ejection head substrate having an electrode pad, including: preparing a substrate on which a first layer is formed, foreign matter being present on a surface of the first layer; forming a mask layer on an entire area of a surface of the substrate, the surface of the substrate being provided with the first layer; removing at least a part of the foreign matter in a height direction by performing an etching treatment on the entire surface of the mask layer; and forming a second layer on a surface on which the etching treatment is performed, wherein the etching treatment is performed so that the foreign matter is not exposed from the second layer after forming the second layer.

Abstract: A printed circuit board according to an embodiment includes a first insulating layer; a second insulating layer disposed on the first insulating layer; a first via portion disposed in the first insulating layer; and a second via portion disposed in the second insulating layer; wherein the first via portion includes: a first via part passing through the first insulating layer; a first-first pad disposed on an upper surface of the first insulating layer and connected to an upper surface of the first via part; and a first-second pad disposed on a lower surface of the first insulating layer and connected to a lower surface of the first via part; wherein the second via portion includes: a second via part passing through the second insulating layer and having a lower surface connected to an upper surface of the first-first pad; a second pad disposed on an upper surface of the second insulating layer and connected to an upper surface of the second via part; wherein a width of the first-first pad is smaller than or e

Abstract: A flexible circuit board includes two first wiring boards, a first adhesive, and a first conductive structure. Each of the two first wiring boards includes a first bent portion, and two first bent portions of the two wiring boards is connected to each other. The first adhesive layer is sandwiched between the two first bent portions. The first conductive structure penetrates the two first bent portions and the first adhesive layer and electrically connects the two first bent portions.

Abstract: Systems, methods, and devices related to catalyzed metal foils are disclosed. Contemplated metal foils have a bottom surface, preferably roughened to Ra of at least 0.1 ?m, bearing a catalyst material. The metal foils are etchable, typically of aluminum or derivative thereof, and is less than 500 ?m thick. Methods and systems for forming circuits from catalyzed metal foils are also disclosed. The catalyst material bearing surface of the metal foil is applied to a substrate and laminated, in some embodiments with a thermoset resin or thermoplastic resin therebetween or an organic material first coating the catalytic material. The metal foil is removed to expose the catalyst material, and a conductor is plated to the catalyst material.

Abstract: A module includes a substrate including a first main surface, a columnar conductor arranged on the first main surface, a first sealing resin that seals at least the columnar conductor and the first main surface while exposing a first end surface of the columnar conductor, a conductive film connected to the columnar conductor and arranged to extend laterally from the first end surface, a resin sheet arranged to cover at least the conductive film, a conductor via provided in the resin sheet and having one end connected to the conductive film, and a conductor pattern arranged on a surface of the resin sheet on a side far from the substrate to be connected to the other end of the conductor via and being larger in area than the first end surface.

Abstract: A semiconductor device includes a low-density substrate, a high-density patch positioned inside a cavity in the low-density substrate, a first semiconductor die, and a second semiconductor die. The first semiconductor dies includes high-density bumps and low-density bumps. The second semiconductor die includes high-density bumps and low-density bumps. The high-density bumps of the first semiconductor die and the high-density bumps of the second semiconductor die are electrically connected to the high-density patch. The low-density bumps of the first semiconductor die and the low-density bumps of the second semiconductor die are electrically connected to the low-density substrate.

Abstract: The present disclosure provides a method for manufacturing a board-to-board connection structure. The method includes defining a first through hole in a first circuit board, disposing a first connector within the first through hole by a first conductive paste, and connecting the first connector to a second circuit board on which a second connector is installed, thereby realizing a connection of the two circuit boards, and reducing a height of the two circuit boards after the connection. That is, the height of the board-to-board connection structure is reduced. Additionally, since the first connector is received within the first through hole, the first connector is not easy to be damaged and oxidized. The present disclosure further provides a board-to-board connection structure manufactured by the above method.

Abstract: The disclosure is directed to a printed circuit board for mechanical support and electrical connection of electrical or electronic components. The printed circuit board has conductive tracks and contact pads carved away or etched from at least one sheet layer of copper laminated onto a non-conductive substrate and has a label attached to the printed circuit board at an intended position before the assembly process. Soldering defects often occur due to the deposition of excessive amounts of solder paste on the contact pads of components adjacent to the label. To prevent soldering defects caused by incorrect solder paste application quantities by simple and inexpensive means, the printed circuit board provides the intended position of the label as a depression with respect to the surroundings thereof.

Abstract: A carrier tape holding device is installed in a component supply unit that supplies a component by drawing a carrier tape storing the component from a tape roll body formed by winding the carrier tape in a roll shape. The carrier tape holding device includes a storage portion that stores the tape roll body. The storage portion holds the tape roll body in a state where the component supply unit is able to draw the carrier tape from the tape roll body, and is capable of receiving a tape roll body for replenishment moved from a holder storing the tape roll body for replenishment in a state where the holder is detachably attached.

Abstract: A printed circuit board includes: a first multilayer substrate including first and second vias adjacent to each other in a stacking direction of the printed circuit board; a second multilayer substrate disposed on the first multilayer substrate in the stacking direction and including third and fourth vias adjacent to each other in the stacking direction; and an adhesive layer connecting respective one surfaces of the first and second multilayer substrates to each other. Each of the first to fourth vias has one surface and the other surface facing the one surface, the one surface being closer to the adhesive layer than the other surface, and the one surface having a larger transverse cross-sectional area than the other surface.

Abstract: A semiconductor structure includes: a first substrate, with a first opening being provided on a surface of first substrate; and a first bonding structure positioned in the first opening. The first bonding structure includes a first metal layer and a second metal layer with a melting point lower than that of the first metal layer. The first metal layer includes a first surface in contact with a bottom surface of the first opening and a second surface opposite to the first surface, the second surface is provided with a first groove, an area, not occupied by the first metal layer and the first groove, of the first opening constitutes a second groove, the second metal layer is formed in the first groove and the second groove, and a surface, exposed from the second groove, of the second metal layer constitutes a bonding surface of the first bonding structure.

Abstract: Implementations of semiconductor packages may include a first substrate coupled to a first die, a second substrate coupled to a second die, and a spacer included within a perimeter of the first substrate and within a perimeter of a second substrate, the spacer coupled between the first die and the second die, the spacer include a junction cooling pipe therethrough.

Abstract: A method for manufacturing a semiconductor device and a semiconductor device produced thereby. For example and without limitation, various aspects of this disclosure provide methods for manufacturing a semiconductor device, and semiconductor devices produced thereby, that comprise forming an interposer including a reinforcement layer.

Abstract: Provided is a probe card, comprising a guide plate and a shielding structure of single-layer or multi-layer. The guide plate comprises an upper surface, a lower surface, and at least one guide hole passing through the upper surface and the lower surface, and the guide hole is provided with an inner wall surface. At least one layer of the shielding structure is made of an electromagnetic absorption material or an electromagnetic reflection material, and the shielding structure is not connected to a ground. Each layer of the shielding structure is formed on the inner wall surface of the guide hole by means of atomic layer deposition or atomic layer etching, and a thickness of each layer is less than 1000 nm.

Abstract: An extracellular potential measurement device includes multiple insulating films each of which is made from an electric insulating material, the insulating films being stacked and bonded to each other; and multiple electrode wires each of which is made from an electroconductive material, the electrode wires being arranged in multiple heights. Each of the electrode wires is interposed between an upper insulating film and a lower insulating film. Each of the insulating films, except for a lowermost insulating film, has an opening penetrating the insulating film. The opening in a lower insulating film has a size that is less than that of the opening in an upper insulating film, the openings in the insulating films being overlapped to form a recess having a size reducing downward, the recess being adapted to store a collection of cells. Each of the electrode wires has an end that is located near an opening in an insulating film that is immediately below the electrode wire, the ends being exposed in the recess.

Abstract: A micromechanical pressure sensor device including a semiconductor base substrate of a first doping type on which an intermediate layer of the first doping type is situated, a cavity sealed by a sealing layer of a second doping type and including a reference pressure, a first grating of the second doping type, suspended inside the cavity on a buried connection region of the second doping type, the buried connection region laterally extending away from the cavity into the semiconductor base material, a second grating of the second doping type, situated on a side of the diaphragm region pointing to the cavity and suspended on the diaphragm region, the first grating and the second grating being electrically insulated from each other and forming a capacitance, a first connection electrically connected to the first grating via the buried connection region, and a second connection electrically connected to the second grating.

Abstract: The present application relates to the technical field of circuit board fabricating, and provides a method for fabricating an asymmetric board, the method includes fabricating a master board, fabricating a second sub-board, thermal compression bonding the master board and the second sub-board, and milling an asymmetric board; further includes at least one of the following three steps: laying copper on the connection areas of the master board except for the second copper layer of an outermost layer to obtain laying copper area, removing copper on the connection areas of the third copper layer, and after the step of milling the asymmetric board, on each of the sub-boards, performing depth control milling at the connection areas from a side of the second sub-board on each sub-board to obtain a depth control groove.

Abstract: A described example includes: a ceramic package having a board side surface and an opposite top side surface; a heat slug mounted to the board side surface of the ceramic package, forming a bottom surface in a die cavity; leads mounted to conductive lands on the ceramic package; sidewall metallization extending from the conductive lands and covering a portion of one of the sides of the ceramic package; copper tungsten alloy conductor layers formed in the ceramic package and spaced by dielectric layers; bond fingers formed of a conductor layer and extending to the die cavity; a semiconductor device mounted over the heat slug, and having bond pads on a device side surface facing away from a surface of the heat slug; electrical connections between bond pads on the semiconductor device and the bond fingers; and a lid mounted to the top side surface of the ceramic package.

Abstract: A display device includes a window member, a display panel, a first adhesive member, and a reinforcing member. The display panel is disposed below the window member. The first adhesive member is disposed between the window member and the display panel. The first adhesive member overlaps the display panel. The reinforcing member is disposed below the display panel such that the display panel is disposed between the window member and the reinforcing member. On a plane of the window member, a first minimum distance from an outermost portion of the window member to an outermost portion of the display panel is equal to a second minimum distance from the outermost portion of the window member to an outermost portion of the first adhesive member.

Abstract: A semiconductor device comprises a substrate including a set of interconnect pads, a die mounted on the substrate, wherein the die includes circuitry that cannot withstand typical lead-free (Pb-free) solder reflow temperature during reflow process, and a reinforcing interposer including a first set of interconnect pads and a second set of interconnect pads. Low temperature solder material connects one of the set of interconnect pads on the substrate to a corresponding one of the first set of interconnect pads on the reinforcing interposer. A printed circuit board includes a set of interconnect pads. Low temperature solder material connects one of the set of interconnect pads of the printed circuit board to a corresponding one of the second set of interconnect pads of the reinforcing interposer. The low temperature solder material has a reflow temperature below typical Pb-free solder material.

Abstract: A semiconductor device has a semiconductor chip having a plurality of pads and wires electrically connected to the plurality of pads, respectively. The plurality of pads includes a plurality of first pads which is electrically connected to a circuit included in the semiconductor chip and to which first wires are bonded and a second pad which is an electrode pad for wire connection test and to which a second wire is bonded.

Abstract: Provided is an electrical connection member including a conductive member made of a rubber-like elastic material, through which a terminal used for supplying power is mounted to a mounted member such as a glass plate, and electrically connected with a small electric resistance to contact member provided in the mounted member, resulting in less reduction of rubber-like elasticity of the conductive member due to a temperature increase of the electrical connection member, even if large current flows. With respect to the conductive member 11 made of the rubber-like elastic material provided in the electrical connection member 10, a compression set measured after the following treatment is 50% or less, the treatment being comprise applying a load between an upper surface and a lower surface of the conductive member and conducting 25% compressive deformation at 105° C. for 22 hours; and electric resistance between the upper surface and the lower surface is 0.1? or less during application of the load.

Abstract: Systems, methods, and devices related to catalyzed metal foils are disclosed. Contemplated metal foils have a bottom surface, preferably roughened to Ra of at least 0.1 ?m, bearing a catalyst material. The metal foils are etchable, typically of aluminum or derivative thereof, and is less than 500 ?m thick. Methods and systems for forming circuits from catalyzed metal foils are also disclosed. The catalyst material bearing surface of the metal foil is applied to a substrate and laminated, in some embodiments with a thermoset resin or thermoplastic resin therebetween or an organic material first coating the catalytic material. The metal foil is removed to expose the catalyst material, and a conductor is plated to the catalyst material.

Abstract: The present invention relates to an electrical connection device and an electronic device comprising same, wherein a receptacle includes a plurality of conductive terminals that are arranged to press a connector in different directions and induces stable contact when the connector is connected to the receptacle.

Abstract: A multilayer resin substrate includes a stacked body including resin layers stacked on each other, a first planar conductor on a resin layer, and an interlayer connection conductor on a resin layer. The interlayer connection conductor includes a first interlayer connection conductor connected to an external conductor, and a second interlayer connection conductor bonded to the first interlayer connection conductor and a planar conductor. The first and second interlayer connection conductors are made of different materials. The second interlayer connection conductor includes a constricted portion including a smaller planar cross-sectional area than a different portion, between a bonding portion to which the first interlayer connection conductor is bonded and a bonding portion to which the planar conductor is bonded.

Abstract: An electronic apparatus includes a display panel including a base substrate including an active area and a peripheral area adjacent to the active area, pixels on the active area, pads on the peripheral area and arranged in a first direction, signal lines connecting the pixels to the pads, and a vernier mark on the peripheral area and spaced apart from the pads and the signal lines, a circuit board on the display panel and including a base film, and leads on the base film and overlapping with the pads in a plan view, and a conductive adhesive member extending in the first direction and between the display panel and the circuit board to connect the pads to the leads. The conductive adhesive member overlaps with the vernier mark when viewed in a second direction intersecting the first direction.

Abstract: A rigid-flex printed circuit board (PCB) includes at least one rigid PCB including at least one electrical component, a flex circuit, and a built-in diagnostic circuit. The flex circuit includes at least one end connected to the at least one rigid PCD. The flex circuit includes at least one signal trace configured to deliver an electrical signal to the at least one electrical component. The built-in diagnostic circuit is configured to detect a fault in the rigid-flex PCB.

Abstract: A glass substrate houses an embedded multi-die interconnect bridge that is part of a semiconductor device package. Through-glass vias communicate to a surface for mounting on a semiconductor package substrate.

Abstract: A device includes a redistribution structure, including conductive features; dielectric layers; and an internal support within a first dielectric layer of the dielectric layers, wherein the internal support is free of passive and active devices; a first interconnect structure attached to a first side of the redistribution structure; a second interconnect structure attached to the first side of the redistribution structure, wherein the second interconnect structure is laterally adjacent the first interconnect structure, wherein the internal support laterally overlaps both the first interconnect structure and the second interconnect structure.

Abstract: A printed circuit board assembly includes a main printed circuit board including a first main signal line and a first dielectric having a first permittivity; a sub printed circuit board including a first sub signal line and a second dielectric having a second permittivity smaller than the first permittivity; and a first connection block configured to connect the first main signal line of the main printed circuit board and the first sub signal line of the sub printed circuit board.

Abstract: A method and device for bonding chips onto a substrate or onto further chips. The chips are bonded onto the substrate or the further chips by means of a direct bond.

Abstract: A manufacturing method of a package structure is provided, which includes the following steps. A carrier having a surface is provided. A copper foil layer is laminated on the surface of the carrier. A subtractive process is performed on the copper foil layer to form a copper foil circuit layer on the carrier. The copper foil circuit layer exposes a part of the surface of the carrier. A build-up structure layer is formed on the copper foil circuit layer and the surface of the carrier. A first surface of the copper foil circuit layer is aligned with a second surface of the build-up structure layer. At least one electronic component is disposed on the build-up structure layer. A package colloid is formed to cover the electronic component and the build-up structure layer. The carrier is removed to expose the first surface of the copper foil circuit layer.

Abstract: The invention relates to methods for drawing-off liquid from individual droplets which are in a predefined arrangement on a flat substrate and have sedimented material enclosed in them. A mask of an absorbent material comprising a pattern of indentations or holes which corresponds at least partially to the regular arrangement of the individual droplets, or a stiff, rigid plate of an absorbent material is positioned above the flat substrate in such a way that the droplets come into contact with the absorbent material peripherally so that liquid is drawn off there-into. The invention also relates to a mask of an absorbent material with a substantially rectangular shape which has a predefined pattern of indentations or holes for the purpose of separating liquid and sedimented material enclosed therein.

Abstract: A display device includes: a display module; a driving chip assembly electrically connected to the display module and including a driving chip and a heat dissipator at least partially surrounding the driving chip; and a main circuit board electrically connected to the driving chip assembly and contacting the heat dissipator.

Abstract: One embodiment of the present disclosure provides a semiconductor package including a bottom chip package having a first side and a second side opposing the first side, and a top antenna package mounted on the first side of the bottom chip package. The bottom chip package further includes a semiconductor chip. The semiconductor chip may include a RFIC chip. The top antenna package has at least one radiative antenna element.

Abstract: A method for manufacturing a multilayer wiring substrate includes forming a resist layer having mask pattern, forming a conductor layer having conductor pattern using the resist layer, removing the resist layer, forming an insulating layer on the conductor layer such that the insulating layer is laminated on the conductor layer, forming a subsequent resist layer having mask pattern such that the subsequent resist layer is formed on the insulating layer, and forming a subsequent conductor layer having conductor pattern using the subsequent resist layer. The forming of the resist layer includes conducting first correction in which formation position of entire mask pattern of the resist layer is corrected with respect to reference position, and conducting second correction in which shape of the mask pattern of the resist layer is corrected with respect to reference shape, and the forming of the subsequent resist layer does not include conducting the second correction.

Abstract: A multilayer ceramic electronic component includes a ceramic body including a dielectric layer, first and second internal electrodes disposed to face each other with the dielectric layer interposed therebetween in the ceramic body, and first and second external electrodes disposed on external surfaces of the ceramic body and electrically connected to the first and second electrodes. At least one of the first and second external electrodes includes a first electrode layer including a first glass and a second electrode layer disposed on the first electrode layer and including a second glass. The first glass contains a larger amount of barium-zinc (Ba—Zn) than the second glass, and the second glass contains a larger amount of silicon (Si) than the first glass.

Abstract: An arrangement, a method of manufacturing component carriers and a component carrier are provided. The arrangement includes a central carrier structure having a front side and a back side, a first layer stack having a first surface structure made of another material than the interior of the first layer stack and covered by a first release layer which is attached to the front side, and a second layer stack covered by a second release layer which is attached to the back side.